# http.py - handle urls with a http scheme # # Copyright (C) 1998, 1999 Albert Hopkins (marduk) # Copyright (C) 2002 Mike W. Meyer # Copyright (C) 2005, 2006 Arthur de Jong # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA # # The files produced as output from the software do not automatically fall # under the copyright of the software, unless explicitly stated otherwise. """This module defines the functions needed for filling in information in Link objects for urls using the http scheme.""" import config import debugio import httplib import urllib import time import urlparse import base64 import socket import re # pattern for extracting character set information from content-type header _charsetpattern = re.compile('charset=([^ ]*)', re.I) # set socket timeout to configured value socket.setdefaulttimeout(config.IOTIMEOUT) def fetch(link, acceptedtypes): """Open connection to url and report information given by GET command.""" # TODO: HTTP connection pooling? # TODO: implement proxy requests for https # split netloc in user:pass part and host:port part (userpass, netloc) = urllib.splituser(link.netloc) proxyuserpass = None scheme = link.scheme # check which host to connect to (if using proxies) if config.PROXIES and config.PROXIES.has_key(link.scheme): # pass the complete url in the request, connecting to the proxy path = urlparse.urlunsplit((link.scheme, netloc, link.path, link.query, '')) (scheme, netloc) = urlparse.urlsplit(config.PROXIES[link.scheme])[0:2] (proxyuserpass, netloc) = urllib.splituser(netloc) else: # otherwise direct connect to the server with partial url path = urlparse.urlunsplit(('', '', link.path, link.query, '')) # remove trailing : from netloc if netloc[-1] == ':': netloc = netloc[:-1] conn = None try: try: # create the connection debugio.debug('schemes.http.fetch: connecting to %s' % netloc) if scheme == 'http': conn = httplib.HTTPConnection(netloc) elif scheme == 'https': conn = httplib.HTTPSConnection(netloc) # the requests adds a correct host header for us conn.putrequest('GET', path) if userpass is not None: (user, passwd) = urllib.splitpasswd(userpass) conn.putheader( 'Authorization', 'Basic '+base64.encodestring(user+':'+passwd).strip() ) if proxyuserpass is not None: (user, passwd) = urllib.splitpasswd(proxyuserpass) conn.putheader( 'Proxy-Authorization', 'Basic '+base64.encodestring(user+':'+passwd).strip() ) # bypass proxy cache if config.BYPASSHTTPCACHE: conn.putheader('Cache-control', 'no-cache') conn.putheader('Pragma', 'no-cache') conn.putheader('User-Agent','webcheck %s' % config.VERSION) conn.endheaders() # wait for the response response = conn.getresponse() link.status = '%s %s' % (response.status, response.reason) debugio.debug('schemes.http.fetch(): HTTP response: %s' % link.status) # dump proxy hit/miss debugging info if config.PROXIES and config.PROXIES.has_key(link.scheme): try: debugio.debug('schemes.http.fetch(): X-Cache: %s' % str(response.getheader('X-Cache'))) except AttributeError: pass # retrieve some information from the headers try: link.mimetype = response.msg.gettype() debugio.debug('schemes.http.fetch(): mimetype: %s' % str(link.mimetype)) except AttributeError: pass try: link.encoding = _charsetpattern.search(response.getheader('Content-type')).group(1) except (AttributeError, TypeError): pass try: link.size = int(response.getheader('Content-length')) debugio.debug('schemes.http.fetch(): size: %s' % str(link.size)) except (KeyError, TypeError): pass try: link.mtime = time.mktime(response.msg.getdate('Last-Modified')) debugio.debug('schemes.http.fetch(): mtime: %s' % time.strftime('%c', time.localtime(link.mtime))) except (OverflowError, TypeError, ValueError): pass # handle redirects # 301=moved permanently, 302=found, 303=see other, 307=temporary redirect if response.status in (301, 302, 303, 307): # consider a 301 (moved permanently) a problem if response.status == 301: link.add_linkproblem(str(response.status)+': '+response.reason) # find url that is redirected to location = urlparse.urljoin(link.url, response.getheader('Location', '')) # create the redirect link.redirect(location) return None elif response.status != 200: # handle error responses link.add_linkproblem(str(response.status)+': '+response.reason) return None elif link.mimetype in acceptedtypes: # return succesful responses # TODO: support gzipped content # TODO: add checking for size return response.read() except httplib.HTTPException, e: debugio.debug('error reading HTTP response: '+str(e)) link.add_linkproblem('error reading HTTP response: '+str(e)) return None except socket.error, e: if hasattr(e, 'args') and len(e.args) == 2: debugio.debug("error reading HTTP response: "+str(e.args[1])) link.add_linkproblem("error reading HTTP response: "+str(e.args[1])) else: debugio.debug("error reading HTTP response: "+str(e)) link.add_linkproblem("error reading HTTP response: "+str(e)) return None finally: # close the connection before returning if conn is not None: conn.close()